A pilot feasibility study was conducted to determine whether Directly Observed Therapy Short-Course (DOTS) workers could be trained to deliver smoking cessation counseling and referral interventions, identify potential barriers to a full-scale randomized controlled trial on the effectiveness of integrated smoking cessation in DOTS, and determine whether tuberculosis (TB) patients who smoke would agree to participate in such a program. DOTS providers in two Rio de Janeiro primary health clinics received 1-day training in cessation counseling. They completed pre- and post-training surveys and participated in post-program focus groups. Patients were surveyed 3 months after program completion, and semiquantitative urine assays for cotinine were used to confirm cessation. Providers' mean self-efficacy scores for cessation counseling improved significantly (advise to quit, assess readiness, assist with quitting, and arrange follow-up) from scores (on a scale of 1-5) of 2-3 pre-training to 3-4 post-training (P < 0.05), with only ability to change motivation not significant. Providers' knowledge about cessation (withdrawal, nicotine replacement therapy, precontemplation) was low before training and did not improve after training (P > 0.1 for all comparisons). Implementation of a smoking cessation intervention by DOTS providers in TB clinics in Brazil is feasible. Randomized controlled trials to test intervention effectiveness in reducing TB-related morbidity must include cross-training for tobacco control and TB providers. Smoking cessation in DOTS programs may be important in reducing the global burden of TB, improving the health of TB patients, and reducing TB transmission in households.